You didnt know these customs were offensive in some countries
Opening a gift in front of the gift-giver: In Asian countries such as China and India opening a gift immediately upon receiving it is seen as being greedy.
Laughing open-mouthed: In Japan laughing while exposing your teeth is considered extremely rude.
Tipping: While many countries have a suggested tip percentage in Japan while the service might be impeccable tipping can be seen as degrading.
Complaining about service: The customer is always right does not always exist in Europe.
Eating with your hands: While it’s the norm to eat with your hands in many parts of South Asia and Africa.
The A-OK sign: In certain countries this hand gesture is crude and offensive and in places like Turkey.
Eating in public: In Japan, eating while walking or in places that are not restaurants is considered both weird and impolite.
Peace sign: In the UK the backwards peace sign is equivalent to flipping someone off.
Crossing your legs: Crossing your legs in parts of the Middle East especially if you're sitting opposite from someone who is older than you is considered a sign of disrespect.